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package controller;

import java.io.IOException;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import model.User;
import model.UserState;

/**
 *
 * @author gsagy
 */
public class FilterAllowOnlyIfNoUser implements Filter {

    private static final boolean debug = true;

    // The filter configuration object we are associated with.  If
    // this value is null, this filter instance is not currently
    // configured. 
    private FilterConfig filterConfig = null;

    public FilterAllowOnlyIfNoUser() {
    } 

    private boolean doBeforeProcessing(ServletRequest request, ServletResponse response)
    throws IOException, ServletException {
    if (debug) log("FilterAllowOnlyIfNoUser:DoBeforeProcessing");

    // Write code here to process the request and/or response before
    // the rest of the filter chain is invoked.

    // For example, a logging filter might log items on the request object,
    // such as the parameters.
    /*
    for (Enumeration en = request.getParameterNames(); en.hasMoreElements(); ) {
        String name = (String)en.nextElement();
        String values[] = request.getParameterValues(name);
        int n = values.length;
        StringBuffer buf = new StringBuffer();
        buf.append(name);
        buf.append("=");
        for(int i=0; i < n; i++) {
            buf.append(values[i]);
            if (i < n-1)
                buf.append(",");
        }
        log(buf.toString());
    }
    */

        boolean valid = false;
        HttpServletRequest httpRequest = (HttpServletRequest)request;
        String urlRequested = httpRequest.getRequestURI();
        HttpSession session = httpRequest.getSession();
        if (session != null)
        {
            User user = (User)session.getAttribute("user");
            if (user == null)
            {
                valid = true;
            }
        }
        return valid;
    } 

    private void doAfterProcessing(ServletRequest request, ServletResponse response)
    throws IOException, ServletException {
    if (debug) log("FilterAllowOnlyIfNoUser:DoAfterProcessing");

    // Write code here to process the request and/or response after
    // the rest of the filter chain is invoked.
    
    // For example, a logging filter might log the attributes on the
    // request object after the request has been processed. 
    /*
    for (Enumeration en = request.getAttributeNames(); en.hasMoreElements(); ) {
        String name = (String)en.nextElement();
        Object value = request.getAttribute(name);
        log("attribute: " + name + "=" + value.toString());

    }
    */

    // For example, a filter might append something to the response.
    /*
    PrintWriter respOut = new PrintWriter(response.getWriter());
    respOut.println("<P><B>This has been appended by an intrusive filter.</B>");
    */
    }

    /**
     *
     * @param request The servlet request we are processing
     * @param response The servlet response we are creating
     * @param chain The filter chain we are processing
     *
     * @exception IOException if an input/output error occurs
     * @exception ServletException if a servlet error occurs
     */
    public void doFilter(ServletRequest request, ServletResponse response,
                         FilterChain chain)
    throws IOException, ServletException {

    if (debug) log("FilterAllowOnlyIfNoUser:doFilter()");

        Throwable problem = null;
    boolean validRequest = doBeforeProcessing(request, response);
        if (validRequest == false)
        {
            // TODO: tell the user he needs to logout to do this
            
            /*
            String messageTitle = "Authorization failure" ;
            String messageBody = "You need to sign in first to access this functionality.";
            Message displayMessage = new Message(messageTitle, messageBody);
            request.setAttribute("displayMessage", displayMessage);

            String userName = CookiesMgr.getCookieValue((HttpServletRequest) request, "userName");
            request.setAttribute("userName", userName);

            request.setAttribute("pageTitle", "Sign in");
            String nextPage = "/signin.jsp?mode=signIn";
            RequestDispatcher dispatcher = request.getRequestDispatcher(nextPage);
            dispatcher.forward(request, response);
            */
        }
        else // if(validRequest == true)
        {
            try
            {
                chain.doFilter(request, response);
            }
            catch(Throwable t)
            {
                // If an exception is thrown somewhere down the filter chain,
                // we still want to execute our after processing, and then
                // rethrow the problem after that.
                problem = t;
                t.printStackTrace();
            }

            doAfterProcessing(request, response);
        }

    // If there was a problem, we want to rethrow it if it is
    // a known type, otherwise log it.
    if (problem != null) {
        if (problem instanceof ServletException) throw (ServletException)problem;
        if (problem instanceof IOException) throw (IOException)problem;
        sendProcessingError(problem, response);
    }
    }
    
    /**
     * Return the filter configuration object for this filter.
     */
    public FilterConfig getFilterConfig() {
    return (this.filterConfig);
    }

    /**
     * Set the filter configuration object for this filter.
     *
     * @param filterConfig The filter configuration object
     */
    public void setFilterConfig(FilterConfig filterConfig) {
    this.filterConfig = filterConfig;
    }

    /**
     * Destroy method for this filter 
     */
    public void destroy() { 
    }

    /**
     * Init method for this filter 
     */
    public void init(FilterConfig filterConfig) { 
    this.filterConfig = filterConfig;
    if (filterConfig != null) {
        if (debug) { 
        log("FilterAllowOnlyIfNoUser:Initializing filter");
        }
    }
    }

    /**
     * Return a String representation of this object.
     */
    @Override
    public String toString() {
    if (filterConfig == null) return ("FilterAllowOnlyIfNoUser()");
    StringBuffer sb = new StringBuffer("FilterAllowOnlyIfNoUser(");
    sb.append(filterConfig);
    sb.append(")");
    return (sb.toString());
    }

    private void sendProcessingError(Throwable t, ServletResponse response) {
    String stackTrace = getStackTrace(t); 

    if(stackTrace != null && !stackTrace.equals("")) {
        try {
        response.setContentType("text/html");
        PrintStream ps = new PrintStream(response.getOutputStream());
        PrintWriter pw = new PrintWriter(ps); 
        pw.print("<html>\n<head>\n<title>Error</title>\n</head>\n<body>\n"); //NOI18N
            
        // PENDING! Localize this for next official release
        pw.print("<h1>The resource did not process correctly</h1>\n<pre>\n"); 
        pw.print(stackTrace); 
        pw.print("</pre></body>\n</html>"); //NOI18N
        pw.close();
        ps.close();
        response.getOutputStream().close();
        }
        catch(Exception ex) {}
    }
    else {
        try {
        PrintStream ps = new PrintStream(response.getOutputStream());
        t.printStackTrace(ps);
        ps.close();
        response.getOutputStream().close();
        }
        catch(Exception ex) {}
    }
    }

    public static String getStackTrace(Throwable t) {
    String stackTrace = null;
    try {
        StringWriter sw = new StringWriter();
        PrintWriter pw = new PrintWriter(sw);
        t.printStackTrace(pw);
        pw.close();
        sw.close();
        stackTrace = sw.getBuffer().toString();
    }
    catch(Exception ex) {}
    return stackTrace;
    }

    public void log(String msg) {
    filterConfig.getServletContext().log(msg); 
    }

}
